Recent Results and Prospects Koichiro Nishikawa (1949-2018) Alain - PowerPoint PPT Presentation

Recent Results and Prospects Koichiro Nishikawa (1949-2018) Alain Blondel 1

Idea of T2K was born 1999-2001 hep-ex/0106019 combining: -- existing SuperKamiokande detector (50kton W.Č., 22.5 kton fiducial) excellent mu/e separation esp. in the sub-GeV region. -- JAERI-KEK Japanese Proton Accelerator Research Complex (JPARC) at TOKAI including a high power, 0.75MW/30GeV Proton Synchrotron neutrino beam from pion decay π + →µ + ν µ -- baseline 295 km � neutrino energy for first maximum is ~650 MeV achievable by pion-decay beam at 2.5 degrees off-axis Alain Blondel T2K latest results and prospects 2

-- designed for ν µ →ν e appearance search (discovered in 2011-13); now main aim is CPV -- Off axis beam � narrow spectrum peak energy given by off axis angle -- Hadron production spectrum measured at CERN (SHINE/NA61) -- thin target (used, 10% on flux) -- replica target (will be used, 5%) 3 Alain Blondel T2K latest results and prospects

Knowledge of off-axis angle provides beam energy scale with % level precision Alain Blondel T2K latest results and 4 prospects

The Off-Axis Near Detector monitors event rates (vs flavour, kinematics, topology) -+- *not* functionally identical to FD UA1/NOMAD magnet donated by CERN -+- but covers full muon momentum -+- and extracts details of interactions --- mostly forward muons Fine grain detector of light material -- one FGD has 50%water layers -- Scintillators with MPPC readout (60’000 channels!) -- TPC tracker in 0.2T magnetic field Alain Blondel T2K latest results and prospects 5

A few ND280 neutrino interaction candidate ν µ quasi-elastic candidate single pion candidate DIS candidate Alain Blondel T2K latest results and prospects 6

Recent T2K publications 1) Search for heavy neutrinos with the T2K near detector ND280 arXiv:1902.07598 [hep-ex]. 2) Search for light sterile neutrinos with the T2K far detector Super-Kamiokande at a baseline of 295 km arXiv:1902.06529 [hep-ex]. 3) Search for neutral-current induced single photon production at the ND280 near detector in T2K arXiv:1902.03848 [hep-ex]. 4) T2K ND280 Upgrade - Technical Design Report arXiv:1901.03750 [physics.ins-det]. 5) Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with $2.2\times10^{21}$ Protons on Target arXiv:1807.07891 10.1103/PhysRevLett.121.171802. Phys.Rev.Lett. 121 (2018) no.17, 171802. 6) Characterization of nuclear effects in muon-neutrino scattering on hydrocarbon with a measurement of final-state kinematics and correlations in charged-current pionless interactions at T2K arXiv:1802.05078 [hep-ex]. 10.1103/PhysRevD.98.032003. Phys.Rev. D98 (2018) no.3, 032003. 7) Measurement of inclusive double-differential νµ charged-current cross section with improved acceptance in the T2K off-axis near detector arXiv:1801.05148 [hep-ex]. 10.1103/PhysRevD.98.012004. Phys.Rev. D98 (2018) 012004. 8) First measurement of the νµ charged-current cross section on a water target without pions in the final state arXiv:1708.06771 [hep-ex]. 10.1103/PhysRevD.97.012001. Phys.Rev. D97 (2018) no.1, 012001. 10) Measurement of νµ and νµ charged current inclusive cross sections and their ratio with the T2K off-axis near detector arXiv:1706.04257 10.1103/PhysRevD.96.052001. Phys.Rev. D96 (2017) no.5, 052001. 11) Measurement of the single π 0 production rate in neutral current neutrino interactions on water arXiv:1704.07467 [hep-ex]. 10.1103/PhysRevD.97.032002. Phys.Rev. D97 (2018) no.3, 032002. Alain Blondel T2K latest results and prospects 7

Alain Blondel T2K results and prospects 8

� ∆ m 2 Energy position of dip 23 � sin 2 2 θ 23 depth of dip ν vs ν � CPT magnitude of peak � sin δ , sin 2 2 θ 13 x sin 2 θ 23 , MH � cos δ , MH ν vs ν � CP position of peak neutrino oscillations in T2K: beam energy peaks at oscillation max. Alain Blondel T2K latest results and prospects 9

sin δ term is CP violating cos δ term is not. sensitivity to δ (precision on δ measurement) is driven by sin δ term if δ is close to 0 or π � rate asymmetry ν e vs ν e cos δ term if δ is close to ±π /2 � E shift, common to ν e and ν e different systematics! 10 Alain Blondel T2K latest results and prospects 10

Beam delivery has been steadily improving to 500kW beam power. Run started in 2009, interrupted by Giant Earthquake (2011) and rad incident (2013) Recent run mostly in anti-neutrino (50% more statistics wrt neutrino 2018 results) Alain Blondel T2K latest results and 11 prospects

Collider-style plot 12 Alain Blondel T2K latest results and prospects

Latest T2K far detector data set Alain Blondel T2K latest results and 13 prospects

Neutrino interaction model Model of single muon events (CC0 π ) are constrained to data. This is very effective for ν µ . Additional errors remain for ν e -- interplay of lepton mass, thresholds and nuclear effects Alain Blondel T2K latest results and prospects 14

T2K flux + near detector event rates are used to predict the event rates at far detector for any set of oscillation parameters within syst. errors ( binding energy) FHC (Forward Horn Current) � (h + focus) � neutrino beam RHC (Reverse Horn Current) � (h - focus) � anti-neutrino beam 1-ring = quasi-elastic interaction 1-ring + 1 decay electron = CC1 π candidate) Binding energy effect is constrained by ν µ events at ND280, but not for ν e 15 Alain Blondel T2K latest results and prospects

Full 3-family analysis on all channels (due to a deficit of obsered ν µ ) 16 Alain Blondel T2K latest results and prospects

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Alain Blondel T2K latest results and 18 prospects

Alain Blondel T2K latest results and 19 prospects

FUTURE PROSPECTS … LOTS! T2K + Wagasci-Baby-MIND full detector to run in spring 2019 SK was open in 2018 starts again in March 2019 filling with Gd for improved ν vs ν rejection (atmo, beam) 2020 ND280 upgrade construction (approved as CERN NP07) *) 2019-2021 JPARC power converter upgrade (double. rep rate) 2021 restart with high power (>750 kW) 2022 RF power upgrade power � 1.3 MW 2023-25 Also requires upgrades in neutrino beam infrastructure aim at > 3 σ (expected, δ =- π /2) by start of HyperK HyperK! seed-funded in 2019 pledged start of construction in 2020 Full data taking starts in ~2027 Also proposed: New Intermediate Water Cherenkov detector Second far detector in Korea *) CERN will become member of T2K 20 Alain Blondel T2K latest results and prospects

Accelerator-based neutrino program in Japan: K2K � T2K � HyperK 21 Super-Kamiokande(50kt) Hyper-Kamiokande (260kt)

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Alain Blondel T2K latest results and prospects 23

Near detector upgrade motivations: 1. θ 13 is large! � syst. dominate 2. Lots learned from running! -- missing: good coverage of large angle leptons -- also e/ γ separation and PID within target � replace upstream part of detector include large angle TPCs surrounding a 3D readout fine grain scintillator detector SFGD (keep FGDs and forward TPCs) � allows full scattering angle coverage with magnetic tracking � SFGD target performance should allow e/ γ separation + investigation of low momentum protons and neutrons beautiful test beam in 2018 � Submitted to JPARC PAC and CERN SPSC � approved (NP07 at CERN) installation to start in 2021 to take data with upgraded beam in 2022. Alain Blondel T2K latest results and 24 prospects

Alain Blondel T2K latest results and prospects 25

Comments: -- if 3.4 σ NH evidence persists, T2K-II + NOvA will not be far from 5 σ by 2026. -- HK saturation at 8 σ driven by assumptions on systematic errors. � strong effort and support to reduce these -- ND280 upgrade, -- Further NA61 measurements -- New IWC near detector (E61) 26 Alain Blondel T2K latest results and prospects 26

E61 1. By combination of fluxes taken at different angles, generate a quasi-monochromatic beam 2. by the same combination of data generate the Energy Response Function 27 Alain Blondel T2K latest results and prospects 27

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SPARES Alain Blondel T2K latest results and prospects 29

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1.49 10 21 POT ν + 1.63 10 21 POT ν Alain Blondel T2K latest results and prospects 31

Baysesian analysis (Markov Chain) A. Kaboth nuphys18 Alain Blondel T2K latest results and prospects 32